Custom-made tissue expanders in reconstructive surgery for challenging skin defects

Background

Tissue expansion is a simple yet versatile surgical technique. Skin defects come in a variety of shapes and dimensions, and in specific reconstructive situations, the catalogued tissue expanders may be of limited suitability producing expanded skin that is not readily compatible with the defect leading to additional scarring and unsatisfactory results. In patients with specific requirements, we have successfully used specially designed tissue expanders to facilitate the reconstruction with reduced morbidity. The aim of the study was to present our experience, indications and outcome of custom-made tissue expanders in resurfacing defects in areas with limited tissue availability.

Methods

Thirty-two textured custom-made tissue expanders were used in 16 patients for skin defects. Indications included eight traumas and eight congenital defects. Custom-made tissue expanders with specified locations for the valves were used in combination with advancement of skin to suit specific reconstructive requirements and minimize scarring.

Results

Custom-made tissue expanders are ideal in certain circumstances to improve the quality of skin reconstruction with reduced morbidity. Skin necrosis was seen in one smoking patient.

Conclusions

In specific reconstructive situations where catalogued tissue expanders are not suitable, custom-made tissue expanders are preferable to optimize results of skin reconstruction with minimal added cost. Level of Evidence: Level IV, therapeutic study.     

The Effects of Low and High Concentrations of Luteolin on Cultured Human Endothelial Cells Under Normal and Glucotoxic Conditions: Involvement of Integrin‐Linked Kinase and Cyclooxygenase‐2

Luteolin protects against high glucose (HG)‐induced endothelial dysfunction whereas its cytotoxicity has been reported against normal endothelial cells. This study was undertaken to determine luteolin cytoprotective and cytotoxic dose ranges and to elucidate their respective mechanisms. Luteolin prevented HG‐induced human umbilical vein endothelial cell (HUVEC) death with an EC50 value of 2.0 ± 0.07 μM. The protective effect of luteolin was associated with decreased intracellular reactive oxygen species (ROS) and Ca²⁺ (Cai²⁺) levels and enhanced nitric oxide (NO) production. At high concentrations, luteolin caused HUVEC death in normal glucose (NG) and HG states (LC₅₀ 40 ± 2.23 and 38 ± 1.12 μM, respectively), as represented by increased ROS and Cai²⁺ and decreased NO. Western blots illustrated that exposure to HG increased cyclooxygenase‐2 (COX‐2) and integrin‐linked kinase (ILK) expression. Luteolin at low concentrations suppressed HG‐mediated up‐regulation of COX‐2 but maintained HG‐induced over‐expression of ILK while at high concentrations significantly increased COX‐2 and decreased ILK expression in both HG and NG states. Our data indicated that cytoprotective action of luteolin was manifested with much lower concentrations, by a factor of approximately 20, compared with cytotoxic activity under both normal or glucotoxic conditions. It appears that luteolin exerts its action, in part, by modulating ILK expression which is associated with regulation of COX‐2 expression and NO production in endothelial cells. Copyright © 2014 John Wiley & Sons, Ltd.     

The origin of nitrogen incorporated into compounds in the rumen bacteria of steers given protein- and urea-containing diets.

1. Two young Friesian steers fitted with rumen cannulas were each given three different isonitrogenous and isoenergetic diets for successive periods of 2-3 weeks. The diets consisted mainly of straw and tapioca, with the nitrogen supplied mainly as decorticated groundnut meal(DCGM; diet A), in approximately equal amounts of DCGM and urea (diet B), or entirely as urea (diet C). 2. At the end of each period on a given diet, part of the dietary urea of a morning feed was replaced by a solution of [15N]urea which was infused into the rumen. Samples of rumen contents were removed just before giving the 15N dose and at 1,3,5,7 and 24 h afterwards, concentrations of ammonia and its 15N enrichment were determined and samples of mixed bacteria were prepared. Amino acids, ammonia derived mainly from amide groups, and hexosamines were prepared by ion-exchange chromatography of acid-hydrolysates of the bacteria and analysed for 15N. 3. Approximate estimates of net bacterial N synthesis were made from turnover data for rumen fluid and 15N enrichments in rumen fractions. From the determined efficiency of incorporation of urea-N into bacteria recovered at the duodenum, it was calculated that on diets A, B and C respectively 82%, 37% and 0% of the bacterial N was derived from dietary protein or other non-urea sources. 4. [15N]urea was converted rapidly to ammonia and the 15N then incorporated into bacterial amide-N; it appeared at a slower rate in total bacterial non-amide-N. Rates of incorporation into non-amide-N were highest for glutamic acid, aspartic acid and alanine, and generally lowest for proline (pro), histidine (his), phenylalanine(phe), arginine(arg), methionine(met) and galactosamine. A similar ranking was also generally observed for relative 15N abundances (15N atoms % excess in N component divided by 15N atoms % excess in total bacterial N) achieved after several hours. Relative 15N abundances in his, arg and pro increased with decreasing protein (DCGM) in the diet but those in the other protein amino acids, including the poorly labelled met, phe (and its derivative tyrosine) did not. 5. It was concluded that different extents of labelling of the amino acids (at least those present mainly in protein) indicated that different amounts of preformed units (amino acids or peptides) were used. When an adequate supply of such units was available (particularly on diet A) pro, arg, his, met and phe were derived in this way to a greater extent than the other amino acids, but whereas synthesis of pro, arg and his increased on the low-protein diet C, that of met and phe did not. Thus met and phe may be limiting for bacterial growth on diets low in protein and high in non-protein-N. 6. Differences in the extent of labelling of other bacterial N components may be due to different turnover rates.     

Terminal branch of anterior interosseous nerve as source of wrist pain

The terminal branch of the anterior interosseous nerve is described anatomically and demonstrated histologically. Injury to this nerve can be the source of persistent, dull aching volar wrist pain. Suitability for partial volar wrist denervation is determined by functional testing before and after a diagnostic nerve block. Experience with twelve patients with this problem is presented.     

Progress in heart transplantation.

The field of heart transplantation was built upon the discoveries of immunity and tolerance by Landsteiner, Medawar, Burnet, and others, as well as technical advancements in surgical technique by Carrel. Since the first successful human heart transplant performed by Christiaan Barnard in 1967, there has been substantial progress in the field of heart transplantation, especially over the last several decades. With advances in immunosuppression and surgical techniques, the rates of acute rejection and infection leading to graft failure have declined. However, the detection of acute and chronic allograft rejection remains one of the most important yet unsettled matters. As such, many new horizons exist for further advancement of the field of heart transplantation and for improving the outcomes of the patients we serve.     

Dual targeting of TNF-α and free radical toxic stress as a promising strategy to manage experimental polycystic ovary

Context: It is now clear that oxidative stress (OS) and chronic low-grade inflammation are two main pathways involved in polycystic ovary syndrome (PCOS) pathogenesis. Therefore, simultaneous targeting of these pathways by means of carvedilol and Semelil (ANGIPARS?), as established medicines with dual anti-cytokine and anti-oxidant potential may be a therapeutic alternative approach to the current treatments.

Objective: The objective of this study is to study the protective effects of carvedilol and ANGIPARS? on inflammatory and oxidative response in hyperandrogenism-induced polycystic ovary (PCO).

Materials and methods: The murine model of PCO was induced by letrozole (1?mg/kg/d; orally) and effective doses of carvedilol (10?mg/kg/d; orally) and ANGIPARS? (2.1?mg/kg/d; orally) were administrated for 21?d in PCO and non-PCO healthy rats. Ovarian folliculogenesis, sex hormones concentrations, OS, inflammatory, and metabolic biomarkers were assessed in serum and ovaries.

Results: PCO rats exhibited ovarian cystogenesis which was preserved by the application of carvedilol and ANGIPARS?. In comparison with controls, decreased level of the total antioxidant power (TAP) and higher levels of reactive oxygen species (ROS) and lipid peroxidation (LPO) in serum and ovaries (2.41?±?0.67 versus 0.72?±?0.11; and 0.17?±?0.04 versus 0.05?±?0.01; 5.48?±?1.30 versus 10.56?±?0.77; and 7.06?±?1.94 versus 17.98?±?0.98; p?<?0.05, respectively) were detected in PCO rats. Moreover, the PCO rats exhibited hyperandrogenism due to a 3.7-fold increase in serum testosterone concentration (35.04?±?3.17 versus 131.09?±?13.24; p?<?0.05) along with a 2.98-fold decrease in serum progesterone (6.19?±?0.40 versus 18.50?±?1.03; p?<?0.05) and 5.2-fold decrease in serum estradiol (9.30?±?0.61 versus 48.3?±?2.10; p?<?0.05) when compared with those of the control group. However, similar to the control group, normal levels of OS markers and sex hormones were detected in ANGIPARS? and carvedilol co-treated PCO rats. Besides, when compared with controls, increased levels of TNF-α (770.75?±?42.06 versus 477.14?±?28.77; p?<?0.05) and insulin (1.27?±?0.10 versus 0.36?±?0.05; p?<?0.05) in PCO rats were significantly inhibited by carvedilol and ANGIPARS? co-treatment.

Discussion and conclusion: We evidenced the beneficial effects of carvedilol and ANGIPARS? in PCO, which underpin the new alternative approach in using these kinds of medicines in female reproductive disorders.     

Surgical Management of Fossa Navicularis and Distal Urethral Strictures

Purpose of Review

Urethral reconstruction has evolved in the last several decades with the introduction of various techniques including fasciocutaneous skin flaps and buccal mucosal grafts. However, distal urethral strictures have continued to be a reconstructive challenge due to tendency for adverse cosmetic outcomes, risks of glans dehiscence or fistula formation, and stricture recurrence.

Recent Findings

The surgical options for treatment of distal urethral strictures have changed throughout the years; however, there is no one universally accepted technique for their treatment. The current trend for treatment is shifting away from multi-staged procedures or the use of local skin flaps to single-stage transurethral procedures that utilize buccal mucosa with glans preservation.

Summary

This chapter will describe the evolution of distal urethral stricture treatments tracking gradual improvements and modifications over time. The different interventions include transurethral approaches, such as dilations and visual urethrotomy, meatotomy, and meatoplasty/urethroplasty techniques including genital skin flaps and single- and double-stage repairs with buccal mucosal grafts.